#include <guitar/uutool.hpp>
#include <common/string.hpp>
#include <common/stdio.hpp>

String UUTool::encode(String strLine)
{
  int stringLength=strLine.length();
	char *ptrBuff;
	int byteCount;

	if(!stringLength)return String();
  String lineString;
	char *ptrLine=lineString.str();
	*(ptrLine++)=chEncode(stringLength);
	for(ptrBuff=strLine.str(),byteCount=stringLength;byteCount>0;byteCount-=3,ptrBuff+=3)
	{
		*(ptrLine++)=chEncode(*ptrBuff>>2);
    *(ptrLine++)=chEncode((*ptrBuff<<4)&0x30|(ptrBuff[1]>>4)&0x0F); 
    *(ptrLine++)=chEncode((ptrBuff[1]<<2)&0x3C|(ptrBuff[2]>>6)&0x03); 
    *(ptrLine++)=chEncode(ptrBuff[2]&0x3F);
	}
	return lineString;
}

String UUTool::decode(String strLine)
{
  int stringLength=strLine.length();
	char *ptrBuff;
	char *ptrLine;
	int byteCount;
	int n;
	char ch;

	if(!stringLength)return String();
  String lineString;
	ptrLine=lineString.str();
	ptrBuff=strLine.str();
  n=chDecode(*(ptrBuff));
	if(n<=0)return String();
	for(++ptrBuff;n>0;ptrBuff+=4,n-=3)
	{
	  if(n>=3)
		{
		  ch=chDecode(ptrBuff[0])<<2|chDecode(ptrBuff[1])>>4;
			*(ptrLine++)=ch;
			ch=chDecode(ptrBuff[1])<<4|chDecode(ptrBuff[2])>>2;
			*(ptrLine++)=ch;
			ch=chDecode(ptrBuff[2])<<6|chDecode(ptrBuff[3]);
			*(ptrLine++)=ch;
		}
		else 
		{
		  if(n>=1)
			{
			  ch=chDecode(ptrBuff[0])<<2|chDecode(ptrBuff[1])>>4;
				(*ptrLine++)=ch;
			}
			else if(n>=2)
			{
			  ch=chDecode(ptrBuff[1])<<4|chDecode(ptrBuff[2])>>2;
        (*ptrLine++)=ch;
			}
			else if(n>=3)
			{
			  ch=chDecode(ptrBuff[2])<<6|chDecode(ptrBuff[3]);
				(*ptrLine++)=ch;
			}
		}
	}
	return lineString;
}